title: Dose proportionality and pharmacokinetics of oral transmucosal fentanyl citrate.
abstract: BACKGROUND
  The pharmacokinetics of a single dose (15 microg/kg) of oral transmucosal fentanyl citrate (OTFC) have been characterized. A range of doses may eventually be used in clinical practice. The goal of this study was to determine if the pharmacokinetics of OTFC are dose proportional for doses ranging from 200 to 1,600 microg.
  
  
  METHODS
  Twelve healthy male volunteers were studied on four different occasions, receiving 200, 400, 800, and 1,600 microg OTFC in a double-blind, randomized protocol. Venous blood samples were collected at selected times during and after dosing for a 24-h period and assayed for fentanyl using a radioimmunoassay. Maximum concentration, time to maximum concentration, area under the curve, and elimination half-life were determined for each dose administered. In addition, respiratory rate, need for verbal prompting to breathe, and supplemental oxygen requirements were noted.
  
  
  RESULTS
  Mean fentanyl concentration time curves were similarly shaped with increasing doses. Both peak concentrations and area under the curve increased linearly with an increase in dose, whereas time to reach peak serum concentrations did not vary significantly between doses. Except for the 200-microg dose, the apparent elimination half-life remained relatively constant (358-386 min). The incidence of low respiratory rate, supplemental oxygen requirement, and number of breathing prompts significantly increased with increasing doses.
  
  
  CONCLUSIONS
  Oral transmucosal fentanyl citrate exhibits dose-proportional pharmacokinetics over the dose range of 200-1,600 microg.
authors.affiliation: Department of Anesthesiology, University of Utah, Salt Lake City 84132, USA. strei@anesth.med.utah.edu
authors.forename: J B
authors.initials: JB
authors.lastname: Streisand
authors.forename: M A
authors.initials: MA
authors.lastname: Busch
authors.forename: T D
authors.initials: TD
authors.lastname: Egan
authors.forename: B G
authors.initials: BG
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Gay
authors.forename: N L
authors.initials: NL
authors.lastname: Pace
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005283:Fentanyl / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D008297:Male; D009061:Mouth Mucosa
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl